using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace ThreadExercise
{
    internal class Class1
    {
        public void test()
        {
            int[] array = new int[] { 1, 2, 3 };
            Array.BinarySearch(array, 2);
            HashSet<string> ideaHashSet = new HashSet<string>();
            ideaHashSet.Add("");
            string str = "";
            string str1 = "";
            Regex.Replace(str,"^[a~z]", str1[0].ToString());
            string.Concat(str.Substring(1), str.Substring(0, 1));
            Dictionary<string,HashSet<char>> dic = new Dictionary<string, HashSet<char>>();
            dic.Where(x => x.Key.Equals("")).Sum(x => x.Value.Count());
            dic[""].Contains('1');
            List<string> list = new List<string>();
            Stack<int> stack = new Stack<int>();
            stack.Push(1);
            //List<int> list = new List<int>();
            Queue<int> ints = new Queue<int>();
            ints.Enqueue(1);
            ints.Count();
            Math.Abs(2-1);
            ints.FirstOrDefault();
            ints.Clear();
            ints.Min();
            Array.Sort(array);
            //stack.Count() > 0
            //SELECT
        }


        public void 
    }
}
